Most people will remember the triangle area formula from when they went to school. It’s one of the most common geometric shapes and, therefore, is one of the first things you learn.
**The triangle area formula is:**
*Area = 0.5 x B x H*
**B** = the triangle’s base length
**H** = the triangle’s altitude or height
If you can’t find your triangle’s height, then you can also use other methods of finding out the information you need to calculate a triangle’s area.
**SSS = If you know the three sides:**
You can use Heron’s formula if you know the measurements for all three sides of your triangle. This looks likes:
*Area = 0.25 x √ ( (a + b + c) x (-a + b + c) x (a - b + c) x (a + b - c) )*
**SAS = If you know the two sides and the angle between them:**
In the case of knowing two sides and one angle, you use trigonometry, with a formula that looks like this:
*Area = 0.5 x a x b x sin(γ)*
**ASA = If you know two angles and the side between them:**
You have a few options for measuring a triangle’s area if you know a side and the two angles around it. The law of sines and trigonometry both apply in this case.
*Area = a² x sin(β) x sin(γ) / (2 x sin (β + γ))*

For this example, we will assume that we know two sides of a triangle and the angle between those sides.
1. Enter the first side’s length into the calculator
2. Enter the second side’s length into the calculator
3. Identify the angle between those sides (in degrees)
4. Get the answer from the calculator – it’s that easy!

If you think it’s simple to work out a triangle’s area, it’s just as easy to work out the area of an equilateral triangle. You only need to have one side to use the following formula:
*Area = a² x √3 / 4*
You can also use the same triangle area calculator to determine the area of an equilateral triangle. All you need to do is use the sub-section for the triangle’s area with three sides because you know all sides are the same.

Measuring the area of a triangle with a calculator can be fun, but did you know you can do it with other shapes too? There are calculators for all kinds of shapes, including circles, rectangles, hexagons, or another challenging shapes.